Complete hydatidiform mole is a conceptus without an embryo displaying generalized swelling of all the placental villi and gross trophoblastic hyperplasia. It is associatied with a high rick-10 to 20 percent of choriocarcinoma. The complete moles are paternal parthenogenones with a 46,XX or 46,XY karyotype, resulting from duplication of a haploid sperm and dispermy respectively. The partial moles are triploid, the extra haploid set deriving from either parent but mostly from the father. They are associated with an embryo-fetus and evince focal mild-moderate trophoblastic hyperplasia. There has been no case of metastatic disease following a partial molar pregnancy in the literature. In order to establish exact genetic origin and genetic maps of all the complete and partial molar pregnancies, following polymorphic markers will be analysed from the molar tissues and the blood from the patient and her husband: 1. Karyotype and marker analysis by Q, R and C banding techniques. 2. Electrphoretic variant determination of several enzymes by standard starch gel electrophoresis. 3. Restriction fragment length polymorphisms (RFLP) by restriction enzymes. With this in background an attempt will be made to predict the cases of complete hydatidiform moles that lead to choriocarcinoma by isolating the trophoblastic cells, fusing them with mitotic chinese hamster ovary cells and visualizing premature chromatin condensation patterns.